P1525: MANAGEMENT OF AUTOIMMUNE HAEMOLYTIC ANAEMIA DURING PREGNANCY OR POST-PARTUM: AN INTERNATIONAL MULTI-CENTRE EXPERIENCE.
Authors: M. Bortolotti, N. N. Fantini, A. Glenthoj, M. Michel, M. Napolitano, S. Raso, F. Chen, V. McDonald, I. Murakhovskaya, J. M. I. Vos, A. Patriarca, M. E. Mingot-Castellano, D. Prati, W. Barcellini, B. Fattizzo
Journal: HemaSphere (2022)

Background: Autoimmune haemolytic anaemia (AIHA) during pregnancy is a rare finding, and few is known about maternal and foetal outcomes. AIHA may either develop or relapse during gestation and postpartum or be an issue in a patient on active therapy who becomes pregnant. AIHA management during pregnancy and lactation is not standardized and drug use is often limited by safety concerns. Aims: We studied AIHA impact on pregnancy focusing on disease severity, treatment need and maternal/foetal outcome. Methods: Through a multicentric retrospective cohort study, we identified 38 pregnancies occurred in 28 women from 1997 to 2021 in 10 European centres in Italy, Denmark, France, the Netherlands, USA, and Spain. All included patients had a previous AIHA history or developed/exacerbated AIHA during gestation or postpartum. AIHA was classified according to the direct antiglobulin test. Results: We registered 18 warm AIHA (10 IgG; 8 IgG+C3d), 2 cold agglutinin disease, 3 mixed and 5 atypical forms (Table 1). Evans syndrome (i.e., association of AIHA and immune thrombocytopenia or neutropenia) was present in 4. Mean age at AIHA diagnosis was 27 (3-39) and at pregnancy 32 (21-41) years. AIHA diagnosis predated pregnancy in 15 women and had required at least 1 therapy line in all of them, and ≥2 lines in 12 (rituximab, N=7; cytotoxic immunosuppressants, N=6; splenectomy, N=5). Among these 15 patients, 6 had a relapse during pregnancy, 3 during postpartum and 9 were on active treatment at the time of pregnancy (steroids, N=8; cyclosporine, N=1; azathioprine, N=1; the latter stopped after positive pregnancy test). A patient with a previous AIHA, relapsed as immune thrombocytopenic purpura during pregnancy. Further 8 patients had an AIHA onset during gestation and 2 postpartum. A patient had AIHA onset during the postpartum of the 1st pregnancy and relapsed during the 2nd one. In the 20 women experiencing AIHA during pregnancy/postpartum, median Hb and LDH levels were 6,4 g/dL (3,1 – 8,7) and 588 UI/L (269-1631), respectively. Management consisted in blood transfusions (N=10) and prompt establishment of steroid therapy+/-IVIG (N=20), all with response (complete N=13, partial N=7). After delivery, rituximab was necessary in 4 patients and cyclosporine was added in one. Anti-thrombotic prophylaxis was given in 7 patients. Overall, we registered 10 obstetric complications (10/38, 26%), including 4 early miscarriages, a premature rupture of membranes, a placental detachment, 2 preeclampsia, a postpartum infection and a biliary colic. Apart from the case of biliary colic and one of the two cases of preeclampsia, 8/10 complications occurred during active haemolysis and treatment for AIHA. Nine foetal adverse events (9/38, 24%) were reported: a transitory respiratory distress of the new-born in a mother with active AIHA, 3 cases of foetal growth restriction, a preterm birth, an infant reporting neurologic sequelae, a case of AIHA of the new-born requiring intravenous immunoglobulins, blood transfusions and plasma exchange, and 2 perinatal deaths. The latter both occurred in women on active AIHA therapy and were secondary to a massive placental detachment and a symptomatic SARS-CoV-2 infection. Image:Summary/Conclusion: AIHA developing/reactivating during pregnancy or postpartum is rare (about 5%) but mainly severe requiring steroid therapy and transfusions. Importantly, severe maternal and foetal complications may occur in up to 26% of cases mostly associated with active disease, pinpointing the importance of maintaining a high level of awareness. Passive maternal autoantibodies transfer to the foetus seems a rare event.